Brake mechanism



bfls, 1945. A. c. CHAMBERS BRAKE MECHANISM Original Filed Aug. 15, 19593 Sheets-Sheet 1 INVENIDR ATTORNEY l Dec. 18, 1945. A. c. CHAMBERS2,391,129

BRAKE MECHANISM Original Filed'Aug; 15. 1939 s Sheets-Sheet 2 VA aINVEN'IOR BY ALLAN C CHAMBERS ORNEY Dec. 18, 1945.

A. C. CHAMBERS BRAKE MECHANISM Origina]: Filed Aug. 15. 1939 3Sheets-Sheet 3v INVHVYU AuA/v C CHAMBERS ATTORNEY Patented Dec. 18, 1945BRAKE MECHANISM Allan G. Chambers, Detroit, Mich., assignor to BendixAviation Corporation, South Bend, Ind., a corporation of DelawareOriginal application August 15, 1939, Serial No. 290,243, now Patent No.2,297,692, dated Octoher 6, 1942.

Divided and this application August 5, 1942, Serial No. 453,639

,4 Claims. (01488 -152) This invention relates to the power transmissionsystem of an automotive vehicle, and more particularly to means forcontrolling a power transmission system including a so-called fluidconventional design, upon the conclusion of a braking operation when theaccelerator is released and the vehicle is stationary upon an incline.

Another object of the invention is to provide automatically operablemeans including an inertia operated switch operating mechanism forretaining in applied position the brakes of a motor vehicle equippedwith a fluid clutch, a friction clutch and a change-speed transmission,all of conventional design, said operation being effected while thevehicle is being decelerated at or below a predetermined rate.

Another object of the invention is to provide automatically operablemeans including an inertia operated switch operating mechanism forretaining in applied position the brakes of a motor vehicle equippedwith a fluid clutch, a friction clutch and a change-speed transmission,all of conventional design, upon the conclusion of a braking operation,when the accelerator is released and when the vehicle is stationary upona decline not exceeding a predetermined degree.

Yet another object of the invention is to provide, in an automotivevehicle equipped with an internal combustion engine or other powerplant, a fluid clutch, a friction clutch and a manually controlledselective gear transmission, means including an inertia operated switchoperating mechanism for maintaining the brakes of the vehicle appliedafter the vehicle is brought to a stop on level ground or after thevehicle is brought to a stop on an incline.

A further object of my invention is to provide, in an automotivevehicle, a mechanism including an inertia operated switch operatingmechanism for dispensing with the operation of the changespeedtransmission, at the will of the driver, and with such acontrolpreventing movement of the vehicle after it has been brought to astop on an incline or on level ground by merely releasing theaccelerator and then depressing the brake pedal and immediatelythereafter removing the foot therefrom.

The most important object of my invention, however, is to provide asimple and compact switch unit including inertia operated means foropening and closing a switch which constitutes one of the importantelements of the brake holding and no-roll mechanism constituting myinvention.

Other objects of the invention and desirable details of construction andcombinations of parts will become apparent from the following detaileddescription of certain embodiments of the invention, taken inconjunction with the accompanying drawings illustrating saidembodiments, in which:

Figure 1 is a diagrammatic view disclosing the principal elements of themechanism of which my inertia operated switch unit constitutes a part;

Figure 2 is a view disclosing, in section, the solenoid operated checkvalve or so-called noback valve included in the braking system disclosedin Figure 1;

Figure 3 is asectional view, taken on the line 3-3 of Figure 4, of theaccelerator operated breaker switch;

Figure 4 is a sectional view, taken on the line 4-4 of Figure 3, of theaccelerator operated breaker switch;

Figure 5 is a sectional view of another breaker switch for in partcontrolling the operation of the solenoid disclosed in Figure 2,together with a pendulum operated mechanism for operating said switch;and

Figures 6, 7 and 8 are sectional views disc1os ing other embodiments ofpendulum operated mechanism for operating a breaker switch.

Referring to Figure l, disclosing schematically the mechanism of whichthe inertia operated switch unit constituting my invention is a part, 10represents a fluid clutch such, for example, as

v the one now incorporated in many of the presentday automotivevehicles.The brake holding and no-roll mechanism disclosed in Figure 1 isdescribed and claimed in my Patent No. 2.2971592, dated October 6, 1942,and the claims of the present application, a division of said Patent No.2,297,692, are limited to the inertia operated switch operatingmechanism disclosed in Figures 5 to 8 inclusive of this application.

Immediately to the rear of the fluid clutch ID, in the powertransmission mechanism of the vehicle, there is incorporated a frictionclutch I2. These clutches I and I2 are of well-known design, and noclaim is made thereto. Briefly describing the clutches I0 and I2, thefluid clutch I0 includes a rotor or driving element, drivably connectedby a shaft and other conventional mechanisms, not shown. to the powerplant of the vehicle preferably an internal combustion engine I 8. Arotor element of the clutch I0 is filled with oil and houses the statoror driven element'of said clutch. The latter element is drivablyconnected by means of a shaft to the rotor or driving element of thefriction clutch I2. The usual clutch springs bias a driven clutchelement of the friction clutch into engagement with the driving clutchelement, the driven clutch element being connected by means including 'ashaft with the selective change-speed transmission 32. A clutch pedal34, when depressed, effects, by suitable'connections. a disengagement ofthe friction clutch I-2, that is, a movement of "the driven element ofsaid clutch away from the driving elementthereof, and ash'i'ft lever,not shown. serves to operate the change-speed transmission 32.

Describing now the mechanism for controlling the -'operation' oi' thebrakes of the vehicle, this mechanism, "as disclosed in Figure 1,-includes a 'iiyd-raulic brake system of conventional design, saidsystem including a master cylinder 36, the 'oil 'thereinbeing subjectedto a load-when abrake pedal 38 is depressed, said load beingtransmittedvia the oil in'lines llll, 42. 44918;,50, 52 and 51! "to thewheel cylinders 58, 58, B0 and =62 of the four brakes 4, 68. 68 and"!respectively of the vehicle. Myinvention is not limited, how ever,to'th'e use of a'hy'clraulicbrake systemdor,

as *w'illbe "brought out hereinafter, other types of brake systems maybe employed.

Referring now to Figure 2, there is disclosed therein-a check valve orso-ca'lled no-ba'c'k valve "I2, which'va'lveis capable o'f'beingoperated, when and only when a solenoid I4 is energized. to main- "tainthe brakes applied. This valve and its-operating means may be defined asa valve unit 16 said unit including a casing bored to provide a seat 80for a ball check valve member 82. A tubular valve operating member "84,reciprocably mounted within the casing I2, 'is provided with a stem 86,which projects through 'a d'uct 88 and into contact with the ballvalve'member '82. A compression spring 90,housed within the tubularmember 84 and extending within an opening 92 in .a plug 94, serves tomove orbia-s the member Y84 and the ball valve member 82 to thepositions disc'losed'in Figure-2, the ball at this time being :removedtfrom the valve seat'80' to' permit the passage of oil through the duct88. The operationof thesolenoid :14 iscontrolled by an ignition :switch:9 6, an accelerator operated breaker switch 98, disclosed-in detailinFigures 3 and 4, and a pendulum operated breaker switch I00, disclosedtinflgure i-said switches-beingconnected in series with a fbattery "I02.

' The.:accelerator:operatedswitch 98 includes a rigidly mounted" casing104' having pivotally :mounted' :therein at I06 a lever member I08 towhich iissecured'a contact member 0. As disclosed in Figure 4,the'member 108 is movable by a-"sprin'g :"hI2'in'to contact with acontact member ".4; Eand' the "contacts I I0 and I14 may be sep-':-arated to open ithe switch by rotating a pin IIB. FIhis pinisrotatably'mouhted in the casing I05 and is provided afiatportionl'l'scontactible withthe switch operating lever member I08. A 120secured to the .pin H6, to which I crank is connected a link I22, Thelink I22 is connected at its other end to a crank I24 connected to thethrottle of the carburetor I26.

Linkage I28 serves to interconnect the crank I 24 5 with the acceleratorI 30 of the vehicle, and the parts -.of the switch 88 and its operatingmechanism are so constructed and arranged that when the accelerator isreleased to idle the engine the switch is closed. Briefly describing theoperation of :the switch when the acceleratoris released the spring I I2forces the lever I08.downwardly, that is in acfllockwise direction,Figure 3, to move the contact II 0 into engagement with contact H4; andwhen the accelerator is depressed to open the throttle the rotation ofthe pin IIB results in a movement of the edge of flat portion III; tomove the lever member I08 counterclockwise, Figure 3, andopen theswitch.

The preferred embodiment of my invention constitutes the pendulumoperated breaker switch I188 disclosed in Figure 5 and itsoperatingmechanism; Other embodiments, which will be described hereinafter, aredisclosed in Figures 6, 7 and '8. Describing the mechanism disclosed inFigure 5, a rigidly mounted hollow casing I32 :serves to house the"breaker switch I00 and its operating means. The latter includes a lever"I 34 pivotally mounted on a pin I 36 mounted in the casing I32. To theend of the'lever I34 there is fixedly secured a weight or bob I38, saidlever with its weighted end constituting a pendulum. The switch'. 1110comprises contacts I40 and I42 secured respectively to-a pin I41!mounted in the casing and to .a :U-rshap'ed clip -I 46 secured "to theupper end aof'a leverl' l8 pivotally mountedonthe pin I36. Aispring I58is connected at one oi its ends to a tab I52 extending from the clip I16and at its-'other'encttofa projection "I5 extending from the'weight I38;A stop I56 is 'adjustably mounted in the casing I32 and serves toprevent the contact I1l2from being unduly'iorced against the contact 140when 'the vehicle is accelerated. Florwhen the vehicle is:accelerated'the pendulum weight 138 will contact the stop .156 beforethe rounded lend .158 'ofthe "lever will contact a tab portion-M9 lof'the clip I 16. V

' Describing the operation.of themechanismconstituting my invention,shou'ld' the driver elect to leave the transmission in gear, when thevehicle is stoppedion an incline or onlevel ground, and with the.acce'lerator'released, he may do so without disengaging the 'frictionclutch I2. "Under these conditions it is necessary, with the mechanismof my invention, that is, the two clutches, the transmission, the brakesand the brake operatingandcontrollingmeans, to apply thebrakes :butonce. Havingde'pressed the brake "pedal the foot may be removedtherefrom for the brakes remain applied; Furthermore, the'brakes willremain applied, despite release-of the brake pedal, "either whenthe'vehicle is 'brought'to astop upon a decline equal to or notexceeding a predetermined degree or-when the've'hicleis decelerated, as'a'result'of an application of'th'e brakes, "at or belowapredeterminedrate. 'Un'derallother conditions, for example, when theaccelerator "is released and 'the "brakes are applied 'to severelydecelerate the vehicle, the check valve 7 2 remains inoperative as faresult of the 'operation of the spring .90 andthe brakes do not remainapplied after the brake pedal is'released. 7

Continuing the d'escription'o'f the operation of the no-back and:anti-creep mechanism *once the brakepedal is depressed the brakesremain applied, for the valve 12 maythen, but not until then, beoperated. Describing this feature, and referring to Figure 2, when thesolenoid I4 is energized by closing the switches 96, 98 and I06,

the member 84 is drawn to the right to further compress the spring 90,thereby making possible an operation of the check valve I2. The stem 86is moved to the right, thus permitting the ball valve member 82 to beseated by the spring. If the brakes are now applied by depressing. thebrake pedal, the pressure of the brake fluid upon the valve member 32will move the same to the left to compress a return spring I52 andunseat the valve. In this operation the brake fluid moves to the left,as indicated by the arrow in Figure 2, said fluid entering the member 84from the conduit 40 connected to the master cylinder 36 and leaving thevalve unit I6 by way of the conduit 42, as disclosed in Figure 1. Whenthe brake pedal is released, the force exerted, by the return spring I62and by the return springs within the wheel cylinders, upon the brakefluid in the system located between the ball valve member 82 and thewheel cylinders results in said member being moved to right to againseat the valve. The brakes are thus locked in their applied position andare not released until the solenoid I4 is again de-energized to renderthe check valve I2 inoperative. As disclosed in my Patent No. 2,297,692the valve unit I6 may also be incorporated in a vacuum operated brakingsystem of conventional design. When so used the unit I6 is incorporatedin the conduit interconnecting the intake manifold of the internalcombustion engine with the vacuum motor of the system. The brake pedaloperated three-way valve of this brake system is also incorporated insaid conduit said valve being located in the conduit between themanifoldand the unit I6.

Assuming the vehicle to be headed to the right with reference to Figure5, the operation of the switch I will now be described. When the vehicleis on level ground, the elements of the pendulum operated mechanism foroperating said switch assume the release positions disclosed in Figure5. In this position of the parts, including the pin I36, the lever I34,the pendulum weight I38, the clip I46 and the spring I 56, the latterlies in a line to the left of the pin I36, that is, to the left of deadcenter. The spring I50 then functions to exert a load upon the clip I46tending to rotate the same in a counterclockwise direction and to bringthe contacts I40 and I42 into engagement with each other. If the vehicleis brought to a stop upon an incline, the lever I34 and its pendulumweight I38 remain in the straight up and down position disclosed inFigure 5, and the casing I32 and the pin secured thereto assume aposition such that the spring I50 is even farther from the pin I36 thanwhen the vehicle is on level ground. The degree of incline will in allprobability be such as to position the weight I38 in contact with thestop I56. Accordingly, the resulting component of force maintaining thecontacts I40 and I42 in engagement is increased. Should the vehicle bestopped upon a decline of sufficient degree to result in the pin I36being positioned just slightly to the left of the spring I50 as viewedin Figure 5, that is, beyond dead center, then the spring I56 willfunction to snap the clip I46 clockwise to the right and move thecontact I40 away from the contact I42 to open the switch; or should thevehicle be decelerated at or above a certain rate, say flve feet persecond per second, the same action will occur. It follows therefore thatwhen the brake pedal is released, with the accelerator released to closethe switch 98 and the vehicle either positioned or so decelerated as tomaintain the switch I00 closed, the brakes will remain applied.

Summing up the features of the mechanism disclosed in Figure 1, there isprovided a mechanism forefliciently and effectively controlling thepower transmitted from the internal combustion engine to the propellershaft of the vehicle. The change-speed transmission cooperates with thefluid clutch, inasmuch as any one of the first, second, high or reversegear settings of the transmission may be selected to start the vehiclein motion. Should, for example, the vehicle be mired in sand, thetransmission may be placed in low gear: however, on dry and level groundthe fluid clutch will make possible a starting of the vehicle in highgear without choking the engine. The driver may then leave thetransmission in high gear when he coasts the vehicle to a stop, and toprevent creeping of the vehicle after such a stop he has merely toeither apply the brakes by depressing and then releasing the brake pedalor disengage the friction clutch by depressing the clutch pedal. Itshould also be noted that the brake controlling mechanism of myinvention functions as a so-called no-roll or no-back device when thevehicle is braked 'to a stop on an incline: furthermore, the mechanismwill function as a no-roll device after the vehicle is braked to a stopon a slight decline, that is, one which is not of sufficient degree toeffect an opening of the switch I00.

All aforementioned mechanisms, including the two clutches, the brakeoperating and controlling means and the transmission, cooperate tocontrol the transmission of power. The friction clutch I2 cooperateswith the fluid clutch I0 and the transmission 32, for it is desirable attimes, in a vehicle provided with a fluid clutch, to place thetransmission in low or second gear. The brake controlling mechanism,including the check valve I2 and the solenoid I4, cooperate with thefriction clutch and fluid clutch in preventing the vehicle from rollingbackwardly after the vehicle is brought to a stop on certain inclinesand cooperate with said clutches in preventing the vehicle from creepingforwardly after the vehicle is brought to a stop on certain otherinclines. For should the transmission be left in gear when the vehicleis brought to a stop on an incline 'of relatively small degree, the thenapplied brakes will oppose the pulling effect of the fluid clutch toprevent an undesirable forward motion of the vehicle and should theincline be relatively steep the then applied brakes will supplement thepulling effect of the fluid clutch to prevent an undesirable rearwardmotion. Accordingly, with the mechanism of my invention, the driver, bymerely releasing the accelerator and depressing the brake pedal, maystop on any incline without fear of the vehicle moving either forwardlyor backwardly. It is not necessary for him to depress the clutch pedalnor maintain the brake pedal depressed, and under most circumstances itis not necessary for him to depress the clutch pedal and shift gear.

There are disclosed in Figures 6, '7 and 8 other embodiments of pendulumor inertia operated switch mechanism of my invention, any one of whichmay be substituted for the mechanism disclosed in Figure 5.

Referring to Figure 6 and assuming the vehicle headed to the left withreference thereto, a pin "0, extending through a hollow casing 1H2,seriles :as a support andfulcrum for Ea lever 4:!!! having :securedZthereto at lower end-.a weight 1:15. The casing 112 :is secured to {the,vehicle, :andwhen the latter is at .rest on level ground the roundedupper end H8 or the lever Ail-.4 ds spaced from :a :tab H38 extendingfrom a :lever .132; which is also pivotally mounted, that is,"liulcrumedat its lower end upon the pin H0. A spring 1.84, secured at one end to apin 186 fixed' :to-the casing 1! l2 and at its o-ther'end to an opening[88 in the :lever member, serves to bias lever m2 to the positiondisclosed in Figure 7., and :in "this position maintain an electricalmontactimember 8% in engagement with a conitact'cnember '582 of'a"breaker switch 94. Th members 1,98 and i 32 are secured to the lever2M2 and .to :a pin 19% respectively. This pin, which serves a conductor,is mounted in the casing' ll2 "and insulated therefrom by a bush- 'ing49%. .As with the mechanism disclosed in Figure nlead wire is connectedto the pin I95 and the casin 112 .is grounded. When the vehicle isstopped on a relatively steep decline or is 'decelerated at a rate ofsay five or more than five feet per second Per second, the resultingrelative positions of the lever i8? and the lever 1:74 are :such as tobring the rounded end H8 :Qf the lever H4 into contact with the tab 580and rotate the lever i8 2 clockwise against the ten-sinner thespring 16i sufiiciently to move the contact 118.0 away ifromcontact 59-2 and sobreak theswitch I94 to disable the anti-creep and/or or no-backmechanism or the brake system. Howevenif the vehieleis stopped-on levelground -or on :an incline or is accelerated, the end H8 is.iartheriremoved from the tab l Sfiand the contacts 19.0 :and I92 remainin engagement to make possible an operation of said mechanism.

Describing the inertia or pendulum operated switch mechanism disclosedin Figure '7, and assuming the vehicle is headed to the right withrespect thereto, a lever 200 weighted at one of its ends by a pendulummember, is fulcrumed to a pin 2&2 mounted in a casing 2M. fixed to thechassis or a part of the vehicle fixedly secured thereto. When the'caris at rest on level ground .the lever 250 is spaced froma tab 2%extending 'irom a lever 288 which is also fulcrumed upon the pin 2-02;and when the car is being accelerated the. lever 290 contacts a stop 2E5adjustably mounted in the casing 204. However should the "car bedecelerated at or above a predetermined rate or brought to a stop on arelatively steep decline the lever 299 is moved counterclockwiseresulting in a-compression of aspring 2M. This spring normally serves toforce the lever 298 to the left or clockwise thereby forcing electricalcontacts H2 and 2M into engagement; however, when the spring iscompressed by the counterclockwise moving lever the contacts areseparated .and the switch opened. The contact 214 is secured to a pin M3and the contact 212 to a tab 2L5 extending from th lever 208. Thedeceleration factor or steepness of the decline neces- .sary to makepossible an opening of the switch is determined by the adjustment of thespring 2| 0. The stop 2l6 serves to prevent the lever .200 from abuttinga shank portion 218 of the contact 2I2 when the car is beingaccelerated.

There is disclosed in Figure .8 yet another embodimentof inertiaoperated breaker switch of my invention. Describing this unit, andassuming the vehicle headed to the left with respect to this figurealever 220, weighted at one of its ends by :a pendulum weight 221, ispivotally mounted at its pther est upon a pin 22. 2- mounted -'a casing224. A pm 226, *slida'bly mounted in a boss 228 extending from thecasing, is umed to "the right by a spring 229 to force an electrical"contact 230 "into engagement with an electrical contact 232 saidcontacts being secured "respectively to'the pin 22B and a pin 234extending through a bushing 236 mounted in the casing 224. When thevehicle being accelerated is at rest on level ground 'or on an inclinethe lever 22.0 is spaced from a portion 238 constituting a part of the.multidiametered pin 226; accordingly at this time the spring 229 servesto maintain the contacts 230 and 232 in engagement. Should the car bedecelerated at or above 'a predetermined rate or brought to a stop on arelatively steep decline the relative positions of t-he'lever 220 andcasing 224 are then such asto effect a compression of the spring 229 anda consequent se aration of the contacts 230 and 232. A stop 248,adjustably mounted in'the casingservesto prevent the lever fromcontacting the portion 238 should the car .be'jerked when starting thesame "in motion. Accordingly this stop, aswell as the stops I56 and 2H5,serve to prevent the lever from damagingthecontacts.

Although this invention has been described in connection with certainspecific embodiments. the principles involved are susceptible ofnumerous other a plications that w ll read ly occur tonerscns skilled inthe art. "The invention is, thereforegtobe limitedonlyas indicated bythe scope of-theappendedclaims.

Iclaim:

1. In a vehicle brake system provided with means operative, after thebrakes are applied, for maintaining the same applied'whenthe velrcle ison any incline, at rest on level ground-or when the vehicle isdecelerating at or below a predetermined rate, said means including .a 7control unit comprising a-casing, a switch mounted within said casing, aspring biasing the movable contact-member of said switch to its-switchclosed position and inertia operated means operative, when and only whenthe vehicle 'is decelerating above a certain rate or the vehicle is atrest on .a decline exceeding a predetermined degree, to move the movablecontact member to its switch open position.

2. In a vehicle brake system provided with means operative, after thebrakes are applied, for maintaining the same applied when the vehicle ison any incline, at rest on level ground or when the vehicle isdecelerating at or below a predetermined rate, said means including acontrol unit comprising a casing, a switch contact secured to saidcasing, a lever fulcrumedupona pin mounted in said casing, a switchcontact secured to said lever, a spring within said .casing operative tobias said lever to a position to bring the switch contacts in engagementwith each other when the vehicle ison an incline, at-rest-onlevelground, or when the vehicle is decelerating at .or below apredetermined rate and inertia operated means 1 operative, when and onlywhen the vehicle is decelerating above a certain rateor the vehicle isat rest on a decline exceeding a predetermineddegree, to move the lever,against the tension of said spring, and thereby move the switch contactsecured to said lever away the s. ten contact secured tothecasing.

3. In a vehicle brake system provided with means operative, after thebrakes areannlied, for maintaining the same applied when the vehicleis-on any incline, at reston level ground or when the vehicle isdecelerating at or below a predetermined rate, said means including acontrol unit comprising a casing, a switch contact secured to saidcasing, a lever fulcrumed upon a pin mounted in said casing, a switchcontact secured to said lever, a spring within said casing operative tobias said lever to a position to bring the switch contacts in engagementwith each other and inertia operated means comprising a lever fulcrumedon the aforementioned pin and having a weighted end portion, saidinertia operated means being operative, when and only when the vehicleis decelerating above a certain rate or the vehicle is at rest on adecline exceeding a predetermined degree, to move the first mentionedlever, against the tension of said Spring, and thereby.move the switchcontact secured to said lever away from the switch contact secured tothe casing.

4. In a vehicle brake system provided with means operative, after thebrakes are applied, for maintaining the same applied when the vehicle ison any incline, at rest on level ground, or when the vehicle isdecelerating at or below a predetermined rate said means including acontrol unit comprising a casing, a switch contact fixedly secured tosaid casing, a contact member movable into and out of engagement withsaid fixed contact member, a spring operative to move said movablecontact member into engagement with said fixed contact member andinertia means connected with said spring, said means comprising a weightmember mounted within said casing and being operative, when and onlywhen the vehicle is decelerating above a certain rate or the vehicle isat rest on a decline exceeding a predetermined degree, to render saidspring operative to move the movable contact member away from the fixedcontact member.

ALLAN C. CHAMBERS.

